The communications regulator ComReg said today that Eircom had breached regulations on customer information by accessing data on other providers' clients.
It gave Eircom, in the process of being taken over by a consortium led by Australian investment group Babcock & Brown, one month to reply to the findings or remedy the practice.
'If at that stage ComReg is of the opinion that Eircom is not in compliance, it may then apply to the High Court for an appropriate order, including a financial penalty,' ComReg said in a statement.
Eircom said that it had been an isolated incident and that it had cooperated fully during the regulator's investigation.
'The company treats any issue of non-compliance very seriously,' it said in a statement.
'Eircom has reviewed its internal processes to prevent any re-occurrence', it added.
The regulator said that in early May 2006, it was alleged that sales agents for Eircom's retail division were able to obtain other operators' customer account numbers directly from Eircom's wholesale systems.
"A subsequent ComReg investigation has yielded evidence which confirms the allegation," it added. "The information is not meant to be made available to any retail operator, including Eircom retail, unless provided by customers themselves."
ComReg said that were Eircom's own retail arm to have direct access to the information, Eircom would have an unfair advantage over its competitors in winning customers.